The transmission rate of the high -speed PCB design wiring system is steadily accelerating, and it also brings the vulnerability of some kind of anti -interference. This is because the higher the frequency of transmission information, the increase of the sensitivity of the signal. At the same time, their energy is getting weaker and weaker. The more vulnerable to the wiring system at this time. Donation is everywhere, cables and devices will interfere with other components or severely interfere with other sources of interference, such as: computer screens, mobile phones, motors, radio broadcast devices, data transmission and power cables. In addition, potential eavesdroppers, cyber crimes and hackers are increasing, as their interception of UTP cable information transmission will cause huge damage and loss.

     Especially when using high -speed data networks, the time required to intercept a large amount of information is significantly lower than the time required to intercept low -speed data transmission. The twisted line in the data twisted line can resist the skewers between the external interference and the line pairs by relying on its own twisted collisions under low frequency, but in the case of high frequency (especially when the frequency exceeds 250MHz), it only depends on The line -to -twisted collisions can no longer achieve the purpose of anti -interference. Only when shielding can resist external interference.

     The function of the cable shielding layer is like a Faraday cover. The interference signal will enter the shielding layer, but it cannot enter the conductor. Therefore, data transmission can run without failure. Because the shielding cable is emitted by lower radiation than the non -shielding cable, it prevents network transmission from being intercepted. The shielded network (shielded cable and component) can significantly reduce the electromagnetic energy radiation level that may be intercepted into the surrounding environment.

     There are mainly electromagnetic interference and radio frequency interference in the shielding fields of different interference fields. Electromagnetic interference (EMI) is mainly low -frequency interference, and motors, fluorescence lamps, and power cords are common sources of electromagnetic interference. RF interference (RFI) refers to wireless frequency interference, mainly high frequency interference. Radio, television broadcasting, radar and other wireless communication are the usual source of radio frequency interference. For resistance electromagnetic interference, choosing weaving shielding is the most effective, because it has a low critical resistance; for radio frequency interference, the foil layer shielding is the most effective. Because the weaving shield depends on the changes in the wavelength, the gap generated by it makes the high -frequency signal freely free Inlet and out of the conductor; for the interference field of high and low -frequency mixed, the combination shielding method with a foil layer with broadband coverage must be adopted. Generally, the higher the mesh shield coverage, the better the shielding effect.